Washing a well



Sept. 2, 1969 T. w. CHILDERS 3,464,495

WASHING A WELL Filed Sept. 11, 1967 1 THOMAS w. EDMOND R N y CHARLES A.BRASIER,

3,464,495 WASHING A WELL Thomas W. Childers, Metairie, Edmond R. Genois,New

Orleans, and Charles A. Brasier, Metairie, La., assignors to EssoProduction Research Company Filed Sept. 11, 1967, Ser. No. 666,623 Int.Cl. E211) 21/00, 33/12 US. Cl. 166-312 9 Claims ABSTRACT OF THEDISCLOSURE BACKGROUND OF THE INVENTION Field of the invention Thepresent invention is directed to method and apparatus for washing debrisfrom a well. More particularly, the invention is concerned with washingsand and the like from a well. In its more specific aspects, theinvention is concerned with washing sand from a well wherein a tubularmember is propelled into the Well and retrieved from the well by fluidpressure, the tubular member following the diminishing level of sand asthe sand is removed and allowing fluid to by-pass around it.

Description of the prior art It is known to wash material from a wellwith a tubular member which seats in and sealed with the lower end ofthe tubing. Such equipment, however, is adaptable to be lowered into andretrieved from substantially vertical wells by wire lines. It is alsoknown to pump well tools into a well having a wellhead on water bottomby fluid circulation. However, the prior art has always provided for thewell tools to be sealed in the lower end of the tubing strings and thusthe only fluid available to remove sand and the like is that pumped downthrough the sealed tool which may be inadequate because of the decreasein velocity by virtue of the large diameter casing. Also, a telescopicmember has been required with the apparatus to permit the tubular memberto follow the sand. The telescopic member would have a limited strokewhich would possibly require several trips to complete the washing. Thisinvention overcomes the limited travel problem and permits the sand tobe washed with one trip in well,

SUMMARY The present invention may be summarized and described as amethod of washing sand and the like from a well casing having at leastfirst and second pipe strings providing a circulation path for fluidextending into a casing to a point above a body of sand and the likecovering perforations in the casing. The fluid circulation path mayinvolve a single pipe string and the annular space between it and thecasing. There is introduced into the first pipe string an elongatedtubular member of suflicient length to extend from the lower end of thefirst pipe string at least to the body of sand, the tubular member beingprovided with means on its trailing free States Patent end forrestricting flow of liquids. Liquid under sufficient pressure isintroduced against the tubular member to cause the tubular member totravel through the first pipe string until the leading free end of thetubular member rests on the body of sand and its trailing free end andrestricting means remain in the pipe string above the interconnectionbetween the two pipe strings. Liquid is continued to be introduced underpressure to wash the sand from the body with the sand flowing up thesecond pipe string intermingled with liquid flowed down the pipe stringand tubular member, the tubular member moving downwardly by pressure ofliquid introduced into the first pipe string as sand is washed up thesecond pipe string until the perforations are uncovered.

The present invention also involves apparatus for use in well casingwhich involves first and second pipe strings fluidly interconnectedadjacent their lower ends; stop means are arranged adjacent the lowerend below the fluid connection. A free elongated tubular member ofselected length is arranged in the first of the pipe strings formovement through the tubular member and is provided with restrictionmeans for exertion of fluid pressure against the restriction means andpermitting passage of fluid through the pipe string, the tubular membermoving through the pipe string to extend therefrom a selected distance;engaging means on the tubular member spaced longitudinally ahead of therestriction means is provided for engaging with the stop means in thelower end of the pipe string below the fluid passage means, such thatwhen the engaging means and stop means engage, the restriction meansremains above the fluid passage. This allows retrieval of the tubularmember by fluid pressure exerted against the restriction means.

BRIEF DESCRIPTION OF THE DRAWING The present invention will be furtherdescribed by reference to the drawing in which:

FIG. 1 illustrates a shore installation terminus of the presentinvention; and

FIG. 2 is a partial sectional view of the well and wellhead; and

FIG. 3 is a sectonal view of the lower portion of a well illustratingthe present invention.

DESCRIPTION OF THE PREFERRED EMBODL MENT AND BEST MODES RELATIVE TO THEDRAWING Referring now to the drawing, and particularly to FIG. 1,numeral 11 designates the shore or a platform adjacent or in a body ofWater 12 having a water surface 13 and a shelving bottom 14 leading outto deep water. A first conduit or line 15 extends from the shore or aplatform 11 to a well and wellhead which will be described further and asecond line 16 likewise extends to the well and wellhead which will bediscussed further. Line 15 is provided with an interconnecting line 17which connects to a manifold 18 with valves 19 and 20 to connect line 17with either the pump 21 which discharges through line 22 or with liquidsource tank 23 through line 24. An adjustable choke 25 is provided toregulate back pressure on return fluids. Line 16 is connected to themanifold 18 by line 26 and valves 27 and 28 control direction of flowfrom line 16. Line 15 is provided with a lubricator section 29 and withvalves 30 and 31 for insertion of well tools such as tubular members andthe like through opening 32. Line 16 is likewise provided with alubricator section 33 and with valves 34 and 35 for insertion of welltools as may be desired through opening 36. Line 15 connects into awellhead, generally indicated by the numeral 56, and line 16 likewiseconnects to the wellhead 56. Lines 15 and 16 are interconnected adjacentthe Wellhead through interconnection means 64 controlled by valve 65. Itis to be noted that lines 15 and 16, respectively, are provided withradius bends 60 and 61 provided with valves 62 and 63. The wellhead 56has vertical line 37 to which line 15 connects by way of bend 60 andvertical line 38 to which line 16 connects by way of bend 61. Both lines37 and 38 are provided with valves 66 and 67 for control thereof asdesired. Lines 37 and 38 extend as tubing strings into the well casing41 which is cemented in well bore 43 by cement sheath 42 filing thespace between the casing 41 and well bore 43. The vertical pipes 37 and38 extend into the casing 41 to a selected distance above perforations44 in the hydrocarbon productive horizon or stratum 45 and hydrocarbonssuch as oil and/or gas may be produced from stratum 45. This is a sandproducing stratum and sand has been produced and accumulated in thecasing 41 to form a body of sand 46 covering the perforations 44 andpreventing production of desirable hydrocarbons.

In order to remove the sand, it is desirable to wash the sand from thecasing and up one pipe string 37 or 38. In this situation, it isdesirable to equip the pipe strings 37 and 38 when they are run in andset with a stop means such as landing nipples 47 and 48 which arearranged respectively in the lower ends of pipe strings 37 and 38. Thisstop means may be other stop means but a suitable J-nipple is describedin the Composite Catalog of Oil Field Equipment and Service, 1966-67,page 3817. With the equipment of both pipe strings 37 and 38 with stopmeans, it is possible to use either one of the pipe strings 37 or 38 inthe present invention. The annular space A between strings 37 and 38 andthe casing 41 is closed by a suitable packing means 49. Such packingmeans are well known in the art.

To remove the sand body 46 in accordance with the present invention, atubular member 50 provided with a plurality of piston members 51 isinserted in the pipe string 16 at the shore 11 and pumped through thepipe string 16 into the pipe string 38 around the radius bend 61. Thepistons 51 are loose-fitting pistons which allow some fluid to passaround the pistons. The pistons may also be designed to allow fluid toflow through a pressure differential valve arrangement positionedbetween the piston wall and the pipe 50. By providing a restrictionmeans, a pressure diflerential allows the tubular member 50 to be pumpedinto the pipe string 38 from the shore 11 by means of pump 21 suppliedwith liquid by conduit 24 and tank 23. The tubular member flows throughthe connection pipe 16, radius bend 34 and down into the pipe string 38until its lower free end 52 provided with a ported nose guide 53 restson and is slightly buried in the sand body 46.

The tubular member 50 is also provided with a shoulder or no-go ring 54which is spaced from the lower piston 51 a sufficient distance such thatthe shoulder 54 engages the landing nipple or stop means 48. The lowerpiston 51 is above the interconnection or passage means 55 connectingthe pipe string 37 with the pipe string 38 adjacent their lower ends.

It is important that the spacing between the shoulder 54 and lowerpiston 51 be selected such that the lower piston 51 is always above theinterconnection 55; thus the distance between shoulder 54 and piston 51is the distance required to maintain the piston above interconnection55. This distance may be from about 1 to 10; feet; usually about 1 tofeet will be sufiicient.

Likewise, the tubular member 50 should extend from the lower end of pipestrings 37 and 38 a distance sufficient to allow removal of sand body46. With the level of perforations 44 known, the tubular member may beof selected length to reach the sand body 46 by extension from the lowerend of pipe strings 37 and 38. This tubular member is of sufficientrigidity to support its own weight but has sufficient flexibility totravel through the various pipe strings connected to the well. This pipemay have a diameter of about A" tubing which will satisfactorily performas indicated.

With the tubular member 50 in the position as shown in FIG. 3, fluidpressure is continued down the pipe 16, the radius bend 61 and pipe 38passing through the tubular member 50 and around the pistons 51. Theportion passing around piston 51 flows through interconnection 55 andthence up the string 57 to pipe 15 and to storage at shore 11 forfurther use and separation of sand therefrom. A portion of the fluidpasses down through the tubular member out of the ported nose guide 53and washes the sand up the casing 41 into the pipe 37. The fluidsentering interconnection 55 increases the flow up the pipe string 38. Asthe level 56 of sand body 46 decreases by removal of sand, the tubularmember by its own weight and force of fluid follows the level of sanddown until the shoulder 54 engages the stop means 48 which signifiesthat the lowest perforation 44 has been uncovered and sand has beenremoved suflicient to allow production of hydrocarbons. When thisoccurs, circulation down pipe string 38 is terminated and circulationdown the pipe string 37 is begun which allows fluid pressure to beimposed on piston 51 and allows the tubular member 50 to be retrievedfrom the pipe string to the shore 11.

In accordance with the present invention, a tubular member 50 having alength of 30 feet extending from pipe 38 may suitably require aboutthree pistons 51. However, any number of pistons may be used dependingon the length of the tubular member 50. Longer tubular members 50 mayrequire more pistons.

Thus, in accordance with the present invention, a method and apparatushave been provided for washing sand and other particulate materialswhich are removable by washing with fluids, such as: fluid cement,debris, and the like, from a well.

The advantages of this invention are (l) the additional fluid whichbypasses the leaky packers increases the flow up the second string,thereby insuring that the sand or debris is flushed from the tubingstring; (2) the need for a telescopic member in the tubular member iseliminated as the tube can follow the top of the sand as it is lowered;and (3) sand washing can be accomplished with one trip in the hole.Thus, a jetting action is provided to remove sand, debris, fluid cementand the like. When the ported nose guide, such as 53, hits the sandbody, such as 46, it may bury itself several inches in the sand. Apiston, such as 51, acting as loose packers, provides a pressuredifferential across each piston. The total pressure differential isapproximately equal to the pressure differential between the top oftubular member 50 and the top of the sand body 46 and allows flowthrough the tubular member 50, and sand and other debris may be Washedout until the shoulder 54 stops in the restriction or stop means 48.

The nature and objects of the present invention having been completelydescribed and illustrated and the best mode and embodiment contemplatedset forth, what we wish to claim as new and useful and secure by LettersPatent is:

1. A method of washing a well having at least two pipe strings arrangedtherein which comprises:

introducing into one of said pipe strings an open-ended tubular memberhaving at least one annular piston adapted to permit fluid to flow pastsaid piston through the annulus between the outer surface of saidtubular member and the inner wall of said one pipe string when fluid isintroduced into said one pipe string to create a pressure differentialacross said tubular mmeber which causes said tubular member to movethrough said one pipe string; and

introducing fluid into said one pipe during under sufficient pressure tomove said tubular member through said one pipe string until one end ofsaid tubular member extends from the lower end of said one pipe string,the fluid circulation path being down said one pipe string and up saidother pipe string.

2. A method in accordance with claim 1 including continuing theintroduction of fluid into said one pipe string and up said other pipestring, while maintaining at least one annular piston in said one pipestring, said fluid when flowing through said one pipe string flowingthrough said open-ended tubular member and also through the annulusbetween the outer surface of said tubular member and the inner wall ofsaid one pipe string past said piston.

3. A method in accordance with claim 2 in which said two pipe stringsare in side-by-side relationship.

4. A method in accordance with claim 3 in which said tubular member isretrieved up said one pipe string by introducing fluid under suflicientpressure into said other pipe string and flowing said fluid down saidother pipe string and up said one pipe string.

5. A method of washing a well having at least two pipe strings arrangedtherein and a body of material to be washed from said well whichcomprises:

introducing into one of said pipe strings an openended tubular member ofselected length and having at least one annular piston adapted to permitflow of fluid past said piston through the annulus between the outersurface of said tubular member and the inner wall of said one pipestring when fluid is introduced into said one pipe string to create apressure diflerential across said tubular member which causes saidtubular member to move through said one pipe string;

introducing fluid under sufiicieni pressure into said one I pipe stringto move said tubular member through said one pipe string until one end01' said tubular member rests on said body of material, the other end ofsaid tubular member being positioned within said one pipe string;

continuing introduction of fluid into said one pipe string undersufficient pressure to wash said body of material from said well up saidother pipe string 'While maintaining at least one annulus piston in saidone pipe string, said circulation flow path for said fluid being downsaid one pipe string through said open-ended tubular member and alsothrough the annulus between the outer surface of said tubular member andthe inner wall of said one pipe string past said piston and then up saidother pipe string;

said material flowing up said other pipe string as it is washed fromsaid well.

6. A method in accordance with claim 5 in which said two pipe stringsare in side-by-side relationship.

7. A method in accordance with claim 6 in which said tubular member ismoved downwardly by said fluid introduced into said one pipe string tofollow the level of said material as said material is washed from saidwell until engaging means on said tubular member engages stop means onsaid one pipe string.

8. A method in accordance with claim 7 in which said tubular member isretrieved up said one pipe string by introducing fluid into said otherpipe string, said circulation flow path being down said other pipestring and up said one pipe string.

9. A method in accordance with claim 8 in which said material washedfrom said well is sand.

References Cited UNITED STATES PATENTS 2,782,860 2/1957 Tauseh et a1.166-44 2,810,442 10/1957 Tausch 166156 3,020,955 2/1962 Tausch 166-443,163,226 12/1964 Lagucki 166156 3,263,753 8/1966 Corley 166-189 JAMESA. LEPPINK, Primary Examiner US. Cl. X.R. 166-155

